The Hadiths are from the book “Fadael al-Sahaba wa Manaqibihim wa Qawl Ba’adihim fi Ba’ad” by the famous scholar of Hadith al-Darqutni, the researcher of this print who graded the narrations is Muhammad Khalifah al-Rabah, the narrations are taken from the chapter “Mentioning what was narrated from the family of Abu Talib and the children of Ali (as) regarding Abu Bakr and Umar (as)“.

We picked some of the narrations whose chains are graded as Authentic (Sahih) or Good (Hasan) and avoided the weak ones:

Ja’afar bin Muhammad from his Father from Abdullah ibn Ja’afar that he said: “May Allah have mercy on Abu bakr he ruled over us and he was the best of rulers, we never met one better than him…”
Grading: Hasan li-Ghayrihi.

Salim ibn Abi Hafsa that he said: I Asked Abu Ja’afar Muhammad ibn Ali and Ja’afar bin Muhammad about Abu Bakr and ‘Umar peace be upon them and they told me: “Ya Salim, be loyal to them and cut your ties from their enemies as they were two Imams of guidance.”
Grading: Hasan.

Salim bin abi Hafsa said: Ja’afar bin Muhammad told me: “Ya Salim would a man insult his grandfather? Abu bakr may Allah be pleased with him is my grand father, may the intercession of Muhammad SAWS never reach me on the day of Judgement if I wasn’t loyal to them and didn’t disassociate myself from their enemies.”
Grading: Hasan.

From Bassam bin Abdullah al-Sayrafi: I asked Abu Ja’afar: What do you say about Abu bakr and ‘Umar may Allah be pleased with them? He replied: “By Allah I am loyal to them and I ask Allah to forgive them and we never met anyone from my family who was not loyal to them.”
Grading: Hasan.

From Isa bin Dinar al-Muatthin the mawla of ‘Amro bin al-Harith al-Khuza’ee: I asked Abu Ja’afar about Abu bakr and ‘Umar and he answered: Muslims may Allah have mercy on them. I told him: Should I be loyal to them and ask Allah to forgive them? He said: Yes. I said: Do you order me to do so? He said: Yes, Yes, Yes (three times) and I take responsibility for what I say. He continued saying: Ali may Allah be pleased with him was in al-Kufa for five years and he always spoke good of them and so did my father and so do I.
Grading: Sahih.

From Ali bin Hisham from his father: I heard Zaid bin Ali say: “If one disassociates himself from Abu Bakr and ‘Umar then he also disassociates himself from Ali may Allah be pleased with him.”
Grading: Hasan li-Ghayrihi.

From Fudayl bin Marzouq that he said: Zaid bin Ali bin al-Hussein said: As for me, If I were in the place of Abu Bakr may Allah be pleased with him I would have ruled the same as he did regarding the land of Fadak.
Grading: Hasan.

From Hilal bin Khabab from al-Hassan ibn Muhammad bin al-Hanafiyyah that he said: “O people of Kufa fear Allah and do not say bad things about Abu Bakr and ‘Umar, Abu bakr was al-Siddiq may Allah be pleased with him and he was the second of the two in the cave with the Prophet PBUH, and as for ‘Umar, Allah had strengthened Islam with ‘Umar.”
Grading: Hasan.

From Abu Khaled al-Ahmar: I asked ‘Abdullah bin al-Hassan about Abu bakr and ‘Umar so he said: “May the peace of Allah be upon them and no peace on those who don’t send peace upon them.”
Grading: Hasan.

From Mus’adah bin al-Yasi’i from Ja’afar bin Muhammad from his father: “During the time of the Prophet SAWS the Family(Aal) of Abu bakr used to be also called the Family(Aal) of Muhammad SAWS.”
Grading: Hasan li-Abu Ja’afar.

From Salim bin abu al-Ja’ad that he was with Muhammad bin Ali in al-Shu’ab: I told him one day:O Abu Abdullah was Abu Bakr the first of the people to accept Islam? Muhammad bin Ali replied: “No he was not.” Then I asked: So how is it that he holds such a high status that everyone keeps speaking of him? He answered me: “Because he was the best of them in Islam when he accepted it and he remained like that until Allah took his soul.”
Grading: Hasan.